1. Field of the Invention
The present invention relates to polypeptides having alpha-glucuronidase activity, catalytic domains, binding domains and polynucleotides encoding the polypeptides, catalytic domains or binding domains. The invention also relates to nucleic acid constructs, vectors, and host cells comprising the polynucleotides as well as methods of producing and using the polypeptides, catalytic domains and binding domains.
A further aspect of the invention relates to the combined action of polypeptides having alpha-glucuronidase activity, and polypeptides having glucuronyl esterase activity.
2. Description of the Related Art
Cellulosic or xylan-containing material can be pretreated before hydrolysis and/or fermentation. Pretreatment is preferably performed prior to the hydrolysis. Alternatively, the pretreatment can be carried out simultaneously with enzyme hydrolysis to release fermentable sugars, such as glucose, xylose, and/or cellobiose. In most cases the pretreatment step itself results in some conversion of biomass to fermentable sugars (even in absence of enzymes).
The purpose of the pretreatment is to improve the rate of production as well as the total yield of liberated sugars in the hydrolysis step. In case of chemical pretreatment, like e.g. acid pretreatment or alkali pretreatment, the type of pretreatment will have different effects on lignocelluloses structural components and thus the enzyme composition used for the hydrolysis step may differ dependent on the pretreatment method. The aim of the present method is to improve hydrolysis of pretreated xylan containing material.
The present invention provides polypeptides having alpha-glucuronidase activity and peptides having glucuronyl esterase activity and polynucleotides encoding the polypeptides. The use of polypeptides having alpha-glucuronidase activity and combinations of polypeptides having alpha-glucuronidase and polypeptides having glucuronyl esterase activity provides methods for improved hydrolysis of in particular xylan containing material.